Add a cron_provider fact

[ekohl]

Similar to package_provider and service_provider the cron provider is useful to know. On some minimal platforms, crontab is not installed and the cron type should not be used. By having a fact for this, it becomes easy to check.

[sheenaajay]

Thanks @ekohl for submitting the PR. Could you please fix the rubocop error. Thank you.

[ekohl]

Updated

[pmcmaw]

As there are inconsistent failures on travis and appveyor I am going to close and reopen your PR to reckick the jobs. :-)

[ekohl]

This is an interesting one to see in the failure (for a different fact):

[2020-05-19 09:28:57.508594 ] ERROR Facter - Error loading fact /home/travis/build/puppetlabs/puppetlabs-stdlib/lib/facter/cron_provider.rb: cannot load such file -- puppet/type/cron 

I can't quite explain that, but should I catch that LoadError in my custom fact?

[pmcmaw]

@ekohl Puppet 6 does not ship with cron as it is now self contained in its own module. For this reason I think that your PR would be better suited to the core cron module: https://github.com/puppetlabs/puppetlabs-cron_core

If you submit it there, please ping me on the PR so I can make sure it gets merged quickly.

[ekohl]

Hmm, that complicates things for my use case. With stdlib I can let my module depend on some release but with the _core modules this isn't really the case. puppetlabs/puppetlabs-cron_core#33 so maybe at some point in the future I can depend on it, but until then I'll create a custom fact in my own module.